Japanese Patent Application Publication No. Hei 11-252833 discloses a field pole magnet for use in a permanent-magnet electric motor. The field pole magnet is a magnet including multiple magnet pieces separated in an axial direction or a circumferential direction of an iron core for the purpose of suppressing heat generation and entirely covered with an insulating layer while being insulated from one another. The field pole magnet is used by being inserted and embedded into each of multiple attachment holes provided respectively in multiple positions at intervals in a circumferential direction of the outer peripheral portion of the iron core of the permanent-magnet motor.
The above document has no description on a method of manufacturing the magnet pieces. However, in a conventionally known method of obtaining a field pole magnet, magnetic slices are produced either by cutting and dividing a magnet with a rotary blade or by power compression molding; and the thus-produced magnet slices are bonded together with an adhesive agent or the like with insulating layers interposed in between.